The U.S. Justice Department is asking an appeals court to lift an injunction issued by a Texas-based federal judge, halting President Barack Obama's executive action against deporting some illegal immigrants.

In their emergency motion filed with the 5th Circuit Court of Appeals in New Orleans Thursday, U.S. attorneys said the judge's ruling last month was "unprecedented and wrong." They said the U.S. constitution does not allow states to "intrude into the uniquely federal domain of immigration enforcement."

They also argued that the injunction undermines the Department of Homeland Security's authority to enforce the law.

The injunction was aimed at putting a temporary hold on the president's order to stop the deportation of as many as 5 million people in the country illegally while the courts hear a lawsuit filed against the president's action.

Twenty-six U.S. states are suing the federal government, saying Obama overstepped his authority.

Obama raised political pressure on the opposition over immigration recently, telling members of Miami's Latino community that Republicans were to blame for stalling the reform.

"For the next set of presidential candidates," he told a town hall meeting hosted by the Spanish-language TV network Telemundo, "when they start asking for votes, the first question should be, 'Are you really going to deport 11 million people? If not, what's your plan?'"

Obama defended his plan and said he disagreed with the federal judge who blocked his order from taking effect. The president said it could take months for an appeals court to overturn that ruling.

He said he remained confident that he was within his legal rights to protect such a broad group of undocumented immigrants, and he urged those who would qualify for the program to continue preparing their applications.

"Until we pass a law through Congress, the executive actions we've taken are not going to be permanent; they are temporary," he said.